The present invention relates to an information recording and reproducing device having a disk recording medium. More particularly, the present invention relates to a method of recording and reproducing information efficiently when an error which requires a retry operation occurs during random access to the information, and relates to an information recording and reproducing device which employs the method.
A hard disk drive is a typical example of an information recording and reproducing device which has a disk recording medium. The hard disk drive is an information recording and reproducing device which records information on a disk magnetic recording medium as magnetization reversals and reproduces information recorded as magnetization reversals by detecting magnetic flux changes. The access time, in which a recording and reproducing head of the information recording and reproducing device accesses to an arbitrary sector, comprises a seek time, in which a seek operation is executed, and rotational delay time, in which the systems waits for the target sector to come under the recording and reproducing head during rotation of the disk medium. It is important to decrease the access time in order to quickly record and reproduce information.
In order to decrease the access time, JP-A-08-329589 discloses a method of accumulating write or read commands in a command queue and sorting the command queue to minimize the rotational delay time of the disk when an error requiring a retry operation does not occur. However, in practice, even though an error occurs in writing or reading information and a retry operation (re-execution of the command) is required, it is important also to reduce the idle waiting time required for a retry operation to improve performance of the disk device.
As an another method to decrease the access time, JP-A-10-124262 discloses a method in which a marginal time which is available for a retry operation is estimated and retry parameters are selected according to the value of this marginal time if an error requiring a retry operation occurs. However, this method is merely an improvement of the above-described example of the conventional technology with regard to a method of setting retry parameters. Namely, for example, it becomes possible to select the number of retry times corresponding to the marginal time by this method.
Further, JP-A-05-325434 discloses a method in which sectors succeeding the error sector are read out and afterward the sector in which an error has occurred is re-read to decrease the rotational delay time, if an error requiring a retry operation occurs in a sector at the time of reading out information from two or more sectors of the hard disk drive.
Besides, JP-A-11-7706 discloses a method in which sectors succeeding the error sector are read out in precedence to decrease the processing time if an error requiring a retry operation occurs while reading out information from two or more sectors within one track in an optical disk device.
According to these methods, when an error requiring a retry operation occurs, the idle rotational delay time can be decreased by reading out successive sectors in precedence. Namely, these methods disclosed in known examples are effective at reading out information from two or more successive sectors on the same track.